.\" Copyright (c) 2016, George V. Neville-Neil
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions are met:
.\"
.\" 1. Redistributions of source code must retain the above copyright notice,
.\"    this list of conditions and the following disclaimer.
.\"
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
.\" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd October 25, 2018
.Dt PKT-GEN 8
.Os
.Sh NAME
.Nm pkt-gen
.Nd Packet generator for use with
.Xr netmap 4
.Sh SYNOPSIS
.Bl -item -compact
.It
.Nm
.Op Fl h46XzZNIWvrAB
.Op Fl i Ar interface
.Op Fl f Ar function
.Op Fl n Ar count
.Op Fl l Ar pkt_size
.Op Fl b Ar burst_size
.Op Fl d Ar dst_ip[:port[-dst_ip:port]]
.Op Fl s Ar src_ip[:port[-src_ip:port]]
.Op Fl D Ar dst_mac
.Op Fl S Ar src_mac
.Op Fl a Ar cpu_id
.Op Fl c Ar cpus
.Op Fl p Ar threads
.Op Fl T Ar report_ms
.Op Fl P Ar file
.Op Fl w Ar wait_for_link_time
.Op Fl R Ar rate
.Op Fl H Ar len
.Op Fl F Ar num_frags
.Op Fl M Ar frag_size
.Op Fl C Ar port_config
.El
.Sh DESCRIPTION
.Nm
leverages
.Xr netmap 4
to generate and receive raw network packets in batches.
The arguments are as follows:
.Bl -tag -width Ds
.It Fl h
Show program usage and exit.
.It Fl i Ar interface
Name of the network interface that
.Nm
operates on.
It can be a system network interface (e.g., em0),
the name of a
.Xr vale 4
port (e.g., valeSSS:PPP), the name of a netmap pipe or monitor,
or any valid netmap port name accepted by the
.Ar nm_open
library function, as documented in
.Xr netmap 4
(NIOCREGIF section).
.It Fl f Ar function
The function to be executed by
.Nm .
Specify
.Ar tx
for transmission,
.Ar rx
for reception,
.Ar ping
for client-side ping-pong operation, and
.Ar pong
for server-side ping-pong operation.
.It Fl n Ar count
Number of iterations of the
.Nm
function, with 0 meaning infinite).
In case of
.Ar tx
or
.Ar rx ,
.Ar count
is the number of packets to receive or transmit.
In case of
.Ar ping
or
.Ar pong ,
.Ar count
is the number of ping-pong transactions.
.It Fl l Ar pkt_size
Packet size in bytes excluding CRC.
If passed a second time, use random sizes larger or equal than the
second one and lower than the first one.
.It Fl b Ar burst_size
Transmit or receive up to
.Ar burst_size
packets at a time.
.It Fl 4
Use IPv4 addresses.
.It Fl 6
Use IPv6 addresses.
.It Fl d Ar dst_ip[:port[-dst_ip:port]]
Destination IPv4/IPv6 address and port, single or range.
.It Fl s Ar src_ip[:port[-src_ip:port]]
Source IPv4/IPv6 address and port, single or range.
.It Fl D Ar dst_mac
Destination MAC address in colon notation (e.g., aa:bb:cc:dd:ee:00).
.It Fl S Ar src_mac
Source MAC address in colon notation.
.It Fl a Ar cpu_id
Pin the first thread of
.Nm
to a particular CPU using
.Xr pthread_setaffinity_np 3 .
If more threads are used, they are pinned to the subsequent CPUs,
one per thread.
.It Fl c Ar cpus
Maximum number of CPUs to use (0 means to use all the available ones).
.It Fl p Ar threads
Number of threads to use.
By default, only a single thread is used
to handle all the netmap rings.
If
.Ar threads
is larger than one, each thread handles a single TX ring (in
.Ar tx
mode), a single RX ring (in
.Ar rx
mode), or a TX/RX ring couple.
The number of
.Ar threads
must be less or equal than the number of TX (or RX) ring available
in the device specified by
.Ar interface .
.It Fl T Ar report_ms
Number of milliseconds between reports.
.It Fl w Ar wait_for_link_time
Number of seconds to wait before starting the
.Nm
function, useuful to make sure that the network link is up.
A network device driver may take some time to enter netmap mode, or
to create a new transmit/receive ring pair when
.Xr netmap 4
requests one.
.It Fl R Ar rate
Packet transmission rate.
Not setting the packet transmission rate tells
.Nm
to transmit packets as quickly as possible.
On servers from 2010 on-wards
.Xr netmap 4
is able to completely use all of the bandwidth of a 10 or 40Gbps link,
so this option should be used unless your intention is to saturate the link.
.It Fl X
Dump payload of each packet transmitted or received.
.It Fl H Ar len
Add empty virtio-net-header with size 'len'.
Valid sizes are 0, 10 and 12.
This option is only used with Virtual Machine technologies that use virtio
as a network interface.
.It Fl P Ar file
Load the packet to be transmitted from a pcap file rather than constructing
it within
.Nm .
.It Fl z
Use random IPv4/IPv6 src address/port.
.It Fl Z
Use random IPv4/IPv6 dst address/port.
.It Fl N
Do not normalize units (i.e., use bps, pps instead of Mbps, Kpps, etc.).
.It Fl F Ar num_frags
Send multi-slot packets, each one with
.Ar num_frags
fragments.
A multi-slot packet is represented by two or more consecutive netmap slots
with the
.Ar NS_MOREFRAG
flag set (except for the last slot).
This is useful to transmit or receive packets larger than the netmap
buffer size.
.It Fl M Ar frag_size
In multi-slot mode,
.Ar frag_size
specifies the size of each fragment, if smaller than the packet length
divided by
.Ar num_frags .
.It Fl I
Use indirect buffers.
It is only valid for transmitting on VALE ports,
and it is implemented by setting the
.Ar NS_INDIRECT
flag in the netmap slots.
.It Fl W
Exit immediately if all the RX rings are empty the first time they are
examined.
.It Fl v
Increase the verbosity level.
.It Fl r
In
.Ar tx
mode, do not initialize packets, but send whatever the content of
the uninitialized netmap buffers is (rubbish mode).
.It Fl A
Compute mean and standard deviation (over a sliding window) for the
transmit or receive rate.
.It Fl B
Take Ethernet framing and CRC into account when computing the average bps.
This adds 4 bytes of CRC and 20 bytes of framing to each packet.
.It Fl C Ar tx_slots[,rx_slots[,tx_rings[,rx_rings]]]
Configuration in terms of number of rings and slots to be used when
opening the netmap port.
Such configuration has effect on software ports
created on the fly, such as VALE ports and netmap pipes.
The configuration may consist of 1 to 4 numbers separated by commas:
.Ar tx_slots , rx_slots , tx_rings , rx_rings .
Missing numbers or zeroes stand for default values.
As an additional convenience, if exactly one number is specified,
then this is assigned to both
.Ar tx_slots
and
.Ar rx_slots .
If there is no fourth number, then the third one is assigned to both
.Ar tx_rings
and
.Ar rx_rings .
.El
.Pp
.Nm
is a raw packet generator that can utilize either
.Xr netmap 4
or
.Xr bpf 4
but which is most often used with
.Xr netmap 4 .
The
.Ar interface name
used depends upon how the underlying Ethernet driver exposes its
transmit and receive rings to
.Xr netmap 4 .
Most modern network interfaces that support 10Gbps and higher speeds
have several transmit and receive rings that are used by the operating
system to balance traffic across the interface.
.Nm
can peel off one or more of the transmit or receive rings for its own
use without interfering with packets that might otherwise be destined
for the host.
For example on a system with a Chelsio Network
Interface Card (NIC) the interface specification of
.Ar -i netmap:ncxl0
gives
.Nm
access to a pair of transmit and receive rings that are separate from
the more commonly known cxl0 interface, which is used by the operating
system's TCP/IP stack.
.Sh EXAMPLES
Capture and count all packets arriving on the operating system's cxl0
interface.
Using this will block packets from reaching the operating
system's network stack.
.Pp
.Nm
-i cxl0 -f rx
.Pp
Send a stream of fake DNS packets between two hosts with a packet
length of 128 bytes.
You must set the destination MAC address for
packets to be received by the target host.
.Pp
.Nm
-i netmap:ncxl0 -f tx -s 172.16.0.1:53 -d 172.16.1.3:53 -D 00:07:43:29:2a:e0
.Sh SEE ALSO
.Xr netmap 4 ,
.Xr bridge 8
.Sh AUTHORS
This manual page was written by
.An George V. Neville-Neil Aq gnn@FreeBSD.org .
